Model for LPS scavenging by β2GPI. (1) Free unbound LPS triggers the innate immune response by binding to a receptor complex that includes TLR4 and CD14 via its Lipid A domain. (2) LPS can be captured by the carboxyterminal 5th domain of β2GPI after a change in the protein's conformation. Domain 5 binds to the non-Lipid A portion of LPS and does not directly neutralize its activity. The opening of β2GPI exposes epitopes that are hypothesized to trigger an autoimmune response leading to antiphospholipid syndrome in susceptible patients. (3) The β2GPI-LPS complex is taken up by LRP, endocytosed, and degraded within the cell. (4) As previously described, β2GPI can also change conformation to bind to membranes that display anionic phospholipids. This binding similarly exposes the epitope on domain 1 that may also trigger an autoimmune response leading to antiphospholipid syndrome. Author's adaptation of Figure 7 of the article by Agar et al¹  executed by Paulette Dennis.